MF Global Holdings Ltd.’s management “seriously underestimated both the speed and extent” of the panic that overtook the securities firm in late October, a bankruptcy trustee said Monday, adding that he might pursue claims against the company’s former CEO, Jon S. Corzine.

According to Giddens, MF Global suffered from a “lack of sufficient monitoring and systems, resulted in customer property being used during the liquidity crisis to fund the extraordinary liquidity drains elsewhere in the business.”

Giddens, who is charged with trying to recover an estimated $1.6 billion for customers of the US brokerage, said the report doesn’t draw conclusions on possible criminal liability. He did say he might sue Corzine and other MF Global executives for claims that include breach of fiduciary duty and negligence. In a summary of the report, Giddens singled out the actions of MF Global Chief Financial Officer Henri Steenkamp and former MF Global Assistant Treasurer Edith O’Brien, who was involved with a key money transfer on Oct. 28, the last trading day before MF Global filed for bankruptcy.

A spokesman for Corzine declined immediate comment. Attempts were being made Monday morning to reach the others.

The report also went into significant detail about Corzine’s strategy of transforming MF Global from a relatively sleepy commodities brokerage operation into one that took the same kinds of risks and trading positions that have been common at large Wall Street banks such as Goldman Sachs.

Three days before MF Global filed for bankruptcy-court protection, CME Group was assured by the New York company of a $200 million cushion in accounts that ensured customer funds were being kept separate from the firm’s own money.

But the customer accounts actually were in the red, and the deficit ballooned to more than $900 million on the night of Oct. 30. MF Global tumbled into Chapter 11 on Oct. 31. The bankruptcy trustee trying to recover money for the firm’s US customers estimated that the shortfall now is roughly $1.6 billion. A large chunk of the money is stuck outside the US.

For at least the past month, representatives of the Commodity Futures Trading Commission and Justice Department and congressional investigators have been asking about the circumstances around the erroneous report and who was responsible for it.

As part of the inquiry, investigators have zeroed in on an accountant at MF Global who expressed concern and confusion to colleagues Oct. 28 about how much money the company had beyond what it held on behalf of customers. Customer money is supposed to be sacrosanct, but MF Global was facing a customer exodus, margin calls and demands for more collateral.

The areas being examined by the House Financial Services Committee’s subcommittee on oversight and investigations include “what was reported to the CME regulators and how that information was produced,” according to a spokeswoman for Rep. Randy Neugebauer (R-Texas), chairman of the subcommittee.

So far, the seven-month civil and criminal investigation has produced no smoking guns that prove anyone at MF Global knowingly raided customer funds. But the conversations now being scrutinized could help regulators and prosecutors piece together exactly how MF Global wound up grabbing so much money from customers.

MF Global was allowed to keep and withdraw its own additional money it kept in customer accounts. But US rules ban futures brokerage firms from diverting segregated customer funds. MF Global blew through the cushion of firm money, leading to a huge shortfall in money belonging to customers.